Biodiversity and Ecological Significance of Gundia River Catchment
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BIODIVERSITY AND ECOLOGICAL SIGNIFICANCE OF GUNDIA RIVER CATCHMENT Gururaja K.V., Sreekantha, Sameer Ali, Rao G. R., Vishnu D. Mukri, & Ramachandra T.V. Energy and Wetlands Research Group, Centre for Ecological Sciences, Indian Institute of Science, Bangalore – 560 012 Web: http://ces.iisc.ernet.in/energy E Mail: [email protected] Summary: The Western Ghats of India is identified as one of the richest regions in terms of biodiversity and it is often referred to as a “biodiversity hotspot”. The Western Ghats is the source of 38 east flowing and 37 west flowing river systems. The ecosystem has experienced tumultuous changes due to river valley and other developmental projects in the last 60 years. Inventorying and monitoring the biodiversity and ecology of river basins would help in the formulation and implementation of appropriate conservation and management strategies in the Western Ghats. This report documents the biodiversity and ecological significance of the Gundia river catchment. This region harbours nearly 36% of plant species, 87% of amphibians, and 41% of fishes, which are endemic to Western Ghats. The presence of four critically endangered and 14 endangered animal species in the region further emphasises the need for conservation of this region on priority as it provides a unique habitat and ecological niche. Considering the ecological significance and rich biodiversity, this region can be declared as an Eco-sensitive region as per sub-section (1) with clause (v) of sub-section (2) of section 3 of the Environment (Protection) Act, 1986 (29 of 1986) and clause (d) of sub-rule (3) of rule 5 of the Environment (Protection) Rules, 1986 in concurrence with the provisions of the Indian Forests Act, 1927 (16 of 1927) and Forest (Conservation) Act, 1980 (69 of 1980) the Wildlife (Protection) Act, 1972 (53 of 1972). 1 BIODIVERSITY AND ECOLOGICAL SIGNIFICANCE OF GUNDIA RIVER CATCHMENT INTRODUCTION Freshwater ecosystems of the tropics and sub-tropics are undergoing rapid deterioration due to developmental pressures, opportunistic exploitation and neglect. The challenging issues here are to improve the current knowledge of its biodiversity so that it would aid in sustainable management of the ecosystem through suitable conservation approaches. The Western Ghats is one among the 34 global hotspots of biodiversity and it lies in the western part of peninsular India in a series of hills stretching over a distance of 1,600 km from north to south and covering an area of about 1,60,000 sq.km. It harbours very rich flora and fauna and there are records of over 4,000 species of flowering plants with 38% endemics, 330 butterflies with 11% endemics, 156 reptiles with 62% endemics, 508 birds with 4% endemics, 120 mammals with 12% endemics (Daniels, 2003), 289 fishes with 41% endemics (Sreekantha et al., 2007) and 135 amphibians with 75% endemics (Gururaja, 2004). Such biodiversity coupled with the higher endemism could be credited to the prevailing climate (higher rainfall, evapotranpiration, etc.), location (mid latitude), topographic, and geological characteristics of the region. Generally, the conservation importance of an area is determined by assessing its ecological values and functions. Assessments are based on the unique habitats and species composition, but in recent times it has been advocated to consider the catchment of a river basin for assessment involving the distribution and abundance of plants and animals within a catchment. This is in a way to bring the linkages between aquatic and terrestrial ecosystems, such an approach was lacking in earlier studies. An important step is to understand the variation in relation to soil type, water status, altitude, etc. This necessitated inventorying, mapping and monitoring of the ecosystem, to arrive at viable conservation and sustainable management strategies. The Gundia River is one of the most important tributaries of river Kumarashara, which in turn is a tributary of Netravathi River. Gundia River is formed by the streams namely Yettinaholé and Kempholé to which the streams Kadumaneholé and Hongadahallé join in the course. More importantly, with a proposal of a power project in Gundia, wherein Karnataka Power Corporation Limited is contemplating to harness the water in the upper reaches of Gundia and Kumaradhara river and their tributaries with an installed capacity of 300 MWs and an annual energy generation of 616 2 MU, this region requires a detailed investigation on the present status of its biodiversity and ecological status. This report focuses on the biodiversity of Gundia river basin, carried out by a multidisciplinary team, which helps to diagnose the adverse effects of the ongoing land use changes on the ecology. This study also addresses the issues like environmental management, restoration of natural ecosystems, restitution of corridors of animal migration and quality of aquatic ecosystems. These are an addition to the benchmark database on existing biodiversity and ecology of the basin. The survey and systematic study was carried out for two days (17th and 18th January 2007) in the catchment area. The main objective of the study was to enlist the species diversity in the region, to highlight the ecological sensitivity of the region. The floral components included are trees, shrubs, herbs, orchids, etc., whereas fauna comprised of butterflies, odonates, fish, amphibians, reptiles, birds and mammals. 3 Study Area Figure 1. Gundia catchment area. 4 b a c d Figure 2. a) Hongadahalla valley view – asset of next generation b) Road creation for the movement of HMV’s. c) Great carvings! Approach roads made through a hillock d) Vateria tree logs - more than 60 years old . 5 Netravathi River and Kumaradhara Rivers of Central Western Ghats, Karnataka are two west flowing rivers. The river systems with numerous perennial streams with typical tropical evergreen forested catchment areas are the regions of high conservation value. Highlights of the riparian vegetation are the naturally grown Vateria indica trees in the upper Ghat region and the presence of Gymnacranthera canarica in the lower reaches of the Ghats. Over 5000 mm of annual rainfall complement to the ecological rich habitats. History of exploitation The Malnad part of the district has seen large scale land cover changes with the overexploitation of vegetation during the last two centuries. It was probably during the direct British rule of the district from 1831 to 1881 that several parts of Malnad was thrown open to the British planters often ex-army men who had changed over to civilian occupation at the end of the Anglo-Mysore wars. Kadamane, Biccodu, Cognur, Karadi-betta, Barchinhullu, Matsagar are only few of the estates dating from this period. The early planters gradually cleared forest tracks and planted them with the shade loving coffee and cardamom, the tall areca and the bushy orange. Tea was introduced at Kadamane in the early twentieth century and now it constitutes one of the major produces of this estate (Saldanha, et al. 1978). Since 1945 there has been a spurt in the plantation industry so that the original vegetation had been greatly altered. There is scarcely any virgin forest in private hands. Major state forests have also been subjected to selective felling of hard structural timbers as well as soft woods for the plywood and matchstick industries. Large tracts of revenue lands with dense evergreen to semi- evergreen forests are being swiftly and completely logged to pave way for other land uses such as plantations. Materials and Methods Random opportunistic sampling of flora and fauna carried out in different habitats in Gundia river catchment (Figure 1 and 2) is listed in Table 1. 6 Table 1: Sampling locations of biodiversity survey Location ° N ° E Elevation Basappan kere 12.76604 75.74252 907 Hongadahalla 12.79995 75.71161 838 Aithalla 12.77285 75.69973 804 Bettakumri halla 12.77362 75.68271 779 Mogerahalli 12.81471 75.71136 756 (Heradanahalli) Kempholé 12.83262 75.65120 277 Kempholé stream 12.83074 75.59398 184 Rare and unidentified specimens were collected for herbaria using dry method. Photographs were taken and geographical co-ordinates of occurrence using global positioning system (GPS) were noted. Fresh specimens were identified with the help of regional and other floras. Apart from primary data, we have also collected secondary data in terms of research papers published, interview and interaction with knowledgeable local people and scientists who earlier worked in the region. This helped in a better understanding of the ecological sensitiveness of the region. Vegetation: The region inherits luxuriant forests, which can be divided broadly into the following types: 1 Tropical wet evergreen to semi-evergreen rain forests: These were extensively found in most of the studied areas with a minimum to various amounts of disturbances. The canopy trees in these forests were over 30 m tall and covered with innumerable climbers and epiphytes. However, the canopy tends to be slightly open with no distinct stratification probably due to removal of old trees (Figure 2d). Some of the trees include 7 Callophyllum apetalum, Lophopetalum wightianum, Dipterocarpus indicus, Myristica dactyloides, Gordonea obtusa, Artocarpus hirsutus, Canarium strictum, Garcinia talbotii, Bischopia javanica, Syzygium gardneri, Holigarma grahamii, etc. Huge trees of Vateria indica had a dominant presence in most of the places along with a large number of seedlings and saplings. Hanging and draping along the trees were climbers such as Gnetum ula, Ancistrocladus heyneanus, Allophylus cobe, Rhaphidophora laciniata, Bauhinia phoenicea, etc. 2 The riparian vegetation: Along the streams and rivulets, species such as Carallia brachiata, Madhuca neriifolia, Euonymus indica, Vateria indica, Calophyllum apetalum, Eleocarpus tuberculatus, etc. were found. In many places stream banks were dominated by reeds such as Cyperus pangorie, Ochlandra scriptoria, etc. Herbs such as Cryptocoryne retrospiralis, Dichanthium huegeli, Rotula aquatica, covered the sandy banks. Homonea riparia, Osmunda regalis, occurs scattered along the stream flow. Cyathea gigantea, occurs in shaded parts of the streams.